PROJECT SUMMARY: In general, the prolonged survival of HIV-infected patients with the use of antiretroviral (ART) therapy has resulted in an increase in the incidence of non-infectious complications including cardio-pulmonary dysfunction. In fact, recent reports suggest that pulmonary vascular remodeling and pulmonary hypertension (PH) precede the airway destruction/emphysema development and that PH and COPD coexist in HIV-infected individuals. Furthermore, IVDU has been found to be the most common risk factor of HIV-infection in the individuals diagnosed with HIV related PH (HRPAH). Our previous findings consistently suggest augmentation of pulmonary vascular dysfunction in HIV infected IVDUs compared to HIV-infected non-drug users or un-infected IVDUs . Therefore, clear understanding of how the drugs of abuse and HIV-infection either alone or in combination cause pulmonary vascular remodeling is urgently needed. Inflammation plays a crucial role in vascular remodeling associated with chronic lung and cardiovascular diseases associated with HIV-infection. We earlier observed significant perivascular inflammation in the lung sections from HIV- infected humans or simian immunodeficiency virus (SIV)-infected macaques exposed to substance of abuse including increased number of macrophages in the remodeled thickened vessels. Based on our recent preliminary findings, we hypothesize that HIV-infection and cocaine mediated alterations in the macrophage derived extracellular vesicles (EVs) promote pulmonary smooth muscle hyperplasia and vascular remodeling by regulating the proliferative signaling cascades on delivery of its cargo to smooth muscle cells . This hypothesis will be tested by pursuing four specific aims. In the first aim using RNA sequencing we will test how EV- miRnome gets influenced on exposure of HIV-infected macrophages to cocaine. In the second aim, we will evaluate the effect of these EVs on smooth muscle function using in-vitro cell-culture system. Third aim will be focused on investigating the in-vivo effect of EVs on pulmonary vascular remodeling and right heart function using HIV-Tg rat model and finally in the fourth aim we will leverage on using human samples from HIV-infected +/- cocaine abusers to correlate the changes in EVs with cardio-pulmonary dysfunction. These studies are innovative because to the best of our knowledge it will be the first attempt to understand the potential link between the macrophage derived EVs and the HIV-1 and cocaine mediated disease progression. The proposed research is significant because this will provide a critical foundation to understand the role of inflammation in the development of HIV-1 and cocaine associated cardio-vascular dysfunction while identifying specific miRNAs in EVs as biomarkers of the disease and /or new targets for preventive and therapeutic interventions in future. Therefore, the proposal is directly responsive to PAS-16-018 entitled ?HIV/AIDS High Priority Drug Abuse Research (R01)? to be funded by National Institute on Drug Abuse (NIDA).